The present invention relates to endless track vehicles such as vehicles which are provided with a swivelling caterpillar track capable of curving at the region of at least one end of the vehicle when the latter executes a turn.
As is well known, such an endless track becomes longer on one side and shorter on the other side when the vehicle executes a turn by turning one or both of the end rolls of the vehicle around which the track moves, and the present invention relates in particular to a method and structure for laterally bracing the endless track when the vehicle executes a turn.
Vehicles having endless tracks capable of contracting on one side while elongating on an opposite side during execution of turns have already been proposed, these vehicles having a swivelling caterpillar track as referred to above.
During the execution of turns with such vehicles it also has already been proposed to provide for lateral bracing of the endless track, and it has already been proposed to provide such lateral bracing at a transverse center line of the vehicle situated between the opposed front and rear ends thereof. Thus, such lateral bracing which has already been proposed includes a pair of fixed horizontal rolls which engage the opposed side margins of the endless track in order to support the latter when the vehicle executes a turn. This type of known lateral bracing, however, has a drawback in that, particularly with heavy loads, the endless track cannot be maintained successfully in a curved configuration. Instead the endless track tends to buckle locally and the direction of the endless track changes abruptly at the bracing rolls.
In order to eliminate this latter drawback it has already been proposed to make at least part of the lateral bracing structure laterally shiftable according to the turning radius of the vehicle so that in this way it will be possible to situate the lateral bracing structure substantially along an arc which is consistent with the turning radius of the vehicle and the endless track thereof. Also, it has been proposed to provide at the side margins of the endless track or at the vicinity thereof a lateral bracing structure which engages the endless track and which is either fixed or displaceable in such a way that when a turn is executed the supporting surface of the endless track shifts so as to always become located at the outer side of the turn. Through such an arrangement an attempt is made to improve the stability of the vehicle when executing turns.
However, with both of the above types of constructions the lateral bracing structure has been situated at the opposed sides of the endless track, in pairs, adjacent to the margins of the track. Such arrangements provide a drawback in that at the regions of this lateral bracing structure undesired detrimental deformations are produced in the endless track. In a track which is made up of a number of components undesirable stresses are created by impact between the lateral bracing structure and the track components.